I expect the answer partly depends on what you can/want to do/learn. There are a number of different jobs in the industry... Artist, programmers, testers, designers... More. They require different skill sets so I would suggest determining your best fit based on what you want to and can do, then first learn how to do that item. The whole 'getting into the industry' thing is no different then getting into anything else... You send a resume (and perhaps a portfolio once you have one) to the company, they put their job openings on their web sites. Getting your foot in the door is hard in all industries, knowing someone helps... Being good at whatever you do also helps... People skills, I wish I had better people skills when I was younger... And show up on time, I shit you not, half of life is showing up on time.

There's umpty zillion different fields, each of which has its own sets of qualifications, career paths, and so on, and that's not even getting into things like the increasingly healthy independent developer scene.

Most of the best-known companies will usually have a stack of job postings sitting around; even if you're not looking to actually respond to one for years, they're a good reference to see the sorts of things companies are looking for.

It's a little talent, a lot of perseverance, and who you know or who you'll blow.